Add complete NexaMFA push MFA system with: - FastAPI backend with PostgreSQL, Redis, OIDC provider, and Prometheus metrics - React TypeScript admin console - Android Kotlin/Jetpack Compose app with biometric authentication - Docker Compose deployment configuration - Gitea CI workflow for backend, frontend, and Android builds - Environment configuration template with security settings - Documentation for security model, deployment
139 lines
5.0 KiB
Python
139 lines
5.0 KiB
Python
from sqlalchemy import select
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from sqlalchemy.ext.asyncio import AsyncSession
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from app.core.config import Settings
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from app.core.security import expires_in, now_utc, random_token, verify_signature
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from app.models.challenge import Challenge, ChallengeStatus
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from app.models.device import Device
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from app.models.user import User
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from app.services.audit import audit
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from app.services.push import PushService
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def build_challenge_payload(challenge: Challenge, username: str) -> dict:
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return {
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"challenge_id": str(challenge.id),
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"user_id": str(challenge.user_id),
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"username": username,
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"relying_party": challenge.relying_party,
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"requester_ip": challenge.requester_ip,
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"location": challenge.location,
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"issued_at": challenge.issued_at.isoformat(),
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"expires_at": challenge.expires_at.isoformat(),
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"nonce": challenge.nonce,
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}
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async def create_challenge(
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session: AsyncSession,
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settings: Settings,
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push: PushService,
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*,
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username: str,
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relying_party: str,
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requester_ip: str,
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location: str | None,
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ttl_seconds: int | None,
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oidc_state: str | None = None,
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) -> Challenge | None:
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user = await session.scalar(select(User).where(User.username == username))
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if not user:
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return None
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device = await session.scalar(
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select(Device)
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.where(Device.user_id == user.id, Device.is_revoked.is_(False))
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.order_by(Device.last_seen_at.desc().nullslast(), Device.created_at.desc())
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)
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if not device:
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return None
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issued = now_utc()
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challenge = Challenge(
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user_id=user.id,
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device_id=device.id,
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relying_party=relying_party,
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requester_ip=requester_ip,
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location=location,
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nonce=random_token(32),
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issued_at=issued,
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expires_at=expires_in(ttl_seconds or settings.challenge_ttl_seconds),
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oidc_state=oidc_state,
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payload={},
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)
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session.add(challenge)
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await session.flush()
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challenge.payload = build_challenge_payload(challenge, user.username)
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await audit(
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session,
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"challenge.created",
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actor=user.username,
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target_type="challenge",
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target_id=str(challenge.id),
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ip_address=requester_ip,
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metadata={"device_id": str(device.id), "oidc": bool(oidc_state)},
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)
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await push.send_challenge(device.fcm_token, str(challenge.id))
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return challenge
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async def expire_if_needed(session: AsyncSession, challenge: Challenge) -> bool:
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if challenge.status == ChallengeStatus.pending and challenge.expires_at <= now_utc():
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challenge.status = ChallengeStatus.expired
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challenge.responded_at = now_utc()
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await audit(session, "challenge.expired", target_type="challenge", target_id=str(challenge.id))
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return True
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return False
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async def approve_challenge(
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session: AsyncSession,
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*,
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challenge: Challenge,
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device_id,
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payload: dict,
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signature: str,
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ip_address: str | None,
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) -> tuple[bool, str]:
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await expire_if_needed(session, challenge)
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if challenge.status != ChallengeStatus.pending:
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await audit(session, "challenge.replay_blocked", target_type="challenge", target_id=str(challenge.id), ip_address=ip_address)
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return False, "challenge_not_pending"
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if str(device_id) != str(challenge.device_id):
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return False, "wrong_device"
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device = await session.get(Device, device_id)
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if not device or device.is_revoked:
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await audit(session, "challenge.revoked_device_blocked", target_type="challenge", target_id=str(challenge.id), ip_address=ip_address)
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return False, "device_revoked"
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if payload != challenge.payload:
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return False, "payload_mismatch"
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if not verify_signature(device.public_key_pem, payload, signature):
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await audit(session, "challenge.signature_invalid", target_type="challenge", target_id=str(challenge.id), ip_address=ip_address)
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return False, "invalid_signature"
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challenge.status = ChallengeStatus.approved
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challenge.signature = signature
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challenge.responded_at = now_utc()
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device.last_seen_at = now_utc()
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await audit(session, "challenge.approved", actor=str(device.user_id), target_type="challenge", target_id=str(challenge.id), ip_address=ip_address, metadata={"device_id": str(device.id)})
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return True, "approved"
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async def deny_challenge(
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session: AsyncSession,
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*,
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challenge: Challenge,
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device_id,
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reason: str | None,
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ip_address: str | None,
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) -> tuple[bool, str]:
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await expire_if_needed(session, challenge)
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if challenge.status != ChallengeStatus.pending:
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return False, "challenge_not_pending"
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if device_id and str(device_id) != str(challenge.device_id):
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return False, "wrong_device"
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challenge.status = ChallengeStatus.denied
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challenge.responded_at = now_utc()
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await audit(session, "challenge.denied", target_type="challenge", target_id=str(challenge.id), ip_address=ip_address, metadata={"reason": reason})
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return True, "denied"
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